JP2015090763A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device, the directly-beneath light intensity of which can be made higher, and which is reduced in glare.SOLUTION: A lighting device 1 includes a light source 2, a substrate 3, and a gutter-shaped cover 4 covering them. The light source 2 has an optical axis H in a normal direction of the substrate 3. The cover 4 includes an incident surface 41 into which light from the light source 2 is incident, and an emission surface 42 from which the light is emitted, where the light is dispersed and emitted from the emission surface 42. The incident surface 41 has a plurality of prisms 43 which control distribution of the incident light. The plurality of prisms 43 are formed so as to collect the light in a prescribed direction including the direction of the optical axis H. According to such a structure, the plurality of prisms 43 formed on the incident surface 41 of the cover 4 collect the light in the prescribed direction including the direction of the optical axis H, thereby making the directly beneath light intensity of the lighting device 1 higher, and the cover 4 has light dispersing properties, thereby enabling reduction in glare.

Description

  The present invention relates to a lighting device installed on a ceiling or the like.

  2. Description of the Related Art Conventionally, a base light type illumination device that is installed on an indoor or outdoor ceiling or the like and irradiates light directly under a space is known. As a conventional general base light type illumination device, it includes two straight tube fluorescent lamps arranged in parallel, a lighting device arranged between the fluorescent lamps, and a cover covered by the lighting device There is something. In many cases, the base light type illumination device is arranged such that a plurality of illumination devices are connected in the tube axis direction of the fluorescent lamp, as in the case of illuminating a linear hallway, for example. For this reason, the single base light type illumination device has a predetermined wide-angle light distribution on a surface perpendicular to the tube axis.

  In recent years, there has been known an illumination device using a straight tube type LED lamp having the same appearance as a straight tube type phosphor and using an LED as a light source (for example, see Patent Document 1). Moreover, the illuminating device provided with the light source part which arranged several LED on the elongate board | substrate in the line form, and the translucent cover which covers this light source part is known (for example, refer patent document 2). ). The LED is capable of emitting light with high power and high luminance, and is widely used as a light source for an illumination device that replaces a fluorescent lamp.

JP 2012-104328 A JP 2013-077400 A

  However, in the conventional general base light type illumination device and the illumination devices described in Patent Documents 1 and 2, two long and thin light sources are used to ensure wide-angle light distribution in a plane perpendicular to the tube axis. The lighting device is arranged in parallel and covered with a cover between them. In such a configuration, the cover may block light from the light source, and the luminous intensity in the direction directly below the lighting device may be low. On the other hand, if the number of LEDs is increased or the light emission output of the LEDs is increased in order to increase the direct luminous intensity of the lighting device, glare is likely to occur in the LED as the point light source, so that the appearance of the lighting device becomes dazzling.

  The present invention solves the above-described problems, and an object of the present invention is to provide an illuminating device that can increase the direct luminous intensity and reduce glare.

  In order to solve the above problems, the present invention is a lighting device including a light source, a substrate on which the light source is mounted, and a bowl-shaped cover that covers the light source and the substrate. The cover has an optical axis in the normal direction, and the cover has an incident surface on which light from the light source is incident and an output surface that emits light incident on the incident surface, and light from the output surface. The incident surface has a plurality of prisms for controlling the light distribution of the light incident on the incident surface, and the plurality of prisms collect light in a predetermined direction including the optical axis direction. It is formed so that it may light.

  In the illumination device, the prism includes a control surface that refracts light incident from the light source, and a non-control surface that is in contact with the control surface and is inclined with respect to the control surface. The surfaces are preferably connected smoothly by the R-shaped part.

  In the illuminating device, in the cross section orthogonal to the longitudinal direction of the cover, the prism is configured so that the non-control surface is in a range of 60 ° or less with the maximum luminous intensity direction of light emitted from the emission surface. It is preferably shorter than the control surface.

  In the illumination device, it is preferable that an angle formed between the control surface and the non-control surface becomes wider as the distance from the maximum luminous intensity direction of light emitted from the emission surface increases.

  In the illuminating device, in the vicinity of the maximum luminous intensity direction of the light emitted from the emission surface, the angle formed by the optical axis of the light source and the non-control surface is larger than 0 °, and the interval p between the adjacent prisms It is preferable that the relationship with the height h of the prism satisfies h ≦ p / 2.

In the illumination device, it is preferable that a relationship between the maximum height h _{max of the} prism and the minimum thickness d _{min of the} cover satisfies h _max ≦ d _min .

  In the illumination device, it is preferable that a convex portion formed by the control surface and the non-control surface of the prism is closer to the substrate as the distance from the maximum luminous intensity direction of light emitted from the emission surface increases.

  In the illuminating device, it is preferable that the cover has a texture or a light scattering agent applied to the incident surface or the emitting surface.

  In the lighting device, the cover is preferably made of a material containing a light diffusing agent.

  According to the present invention, the cover condenses the light in a predetermined direction including the optical axis direction by the plurality of prisms formed on the incident surface on which the light from the light source is incident, so that the brightness just below the illumination device is increased. In addition, since the cover has light diffusibility, dazzling can be reduced.

(A) is a perspective view of the lighting fixture which concerns on one Embodiment of this invention, (b) is a sectional side view of the lighting fixture. (A) is a sectional side view of the cover used for the lighting fixture, (b) is a partially enlarged side sectional view of the cover. (A) is a figure which shows a light distribution curve when a cover is not used in the said lighting fixture, (b) is a figure which shows a light distribution curve when the cover is used. The partial expanded sectional view which shows the modification of the cover. The sectional side view orthogonal to the longitudinal direction of the cover which concerns on the form different from the said embodiment.

  The lighting fixture which concerns on one Embodiment of this invention is demonstrated with reference to FIGS. As shown in FIGS. 1 (a) and 1 (b), the illumination device 1 according to this embodiment includes a light source 2, a substrate 3 on which the light source 2 is mounted, a cover 4 that covers the light source 2 and the substrate 3, and holds them. And a housing 10 to be provided. The external appearance of the illuminating device 1 is a rectangular shape in front view, and has a laterally symmetrical side shape when viewed from the short side direction. The width of the casing 10 in the short direction is smaller than the width of the cover 4. Moreover, the illuminating device 1 is further provided with the power supply part (not shown) which is provided in the inside or the exterior of the housing | casing 10, and drives a light source to light. In addition, the wavy arrow in the figure indicates an example of a light beam whose light distribution is controlled by the cover 4.

  The housing 10 has a construction surface 11 such as a ceiling formed of a flat surface, a mounting surface 12 of the substrate 3 on the surface opposite to the construction surface 11, and both side surfaces connecting both edges of the construction surface 11 and the mounting surface 12. 13. The distance between the side surfaces 13, that is, the width in the short direction of the housing 10 is smaller than the width of the cover 4. The mounting surface 12 has a concave portion 14 along the longitudinal direction at the center thereof, and the long substrate 3 is provided in the concave portion 14. The housing 10 is formed by pressing and cutting a plate material such as an aluminum plate or a steel plate having a predetermined rigidity and heat resistance into the above shape. The mounting surface 12 may be coated with a white paint having a high visible light reflectance, or a reflective metal material may be deposited thereon.

  The light source 2 is composed of LEDs that are point light sources, and a plurality of LEDs are arranged in a line along the longitudinal direction of the substrate 3 at regular intervals. The light source 2 has an optical axis H in the normal direction of the substrate 3. The LED constituting the light source 2 is configured as an LED package by covering with a wavelength conversion member that converts the wavelength of light emitted from the LED chip. The light source 2 is not particularly limited as long as it is a light source that can emit light of a desired light color as the illumination device 1. For example, a YAG fluorescent light is applied to a GaN blue LED chip that emits blue light having an emission peak wavelength of 460 nm. A so-called white LED that covers the body is preferably used. In addition, it is also possible to use a plurality of LEDs having different emission colors, arrange them in a row, and mix the emitted light of each LED to realize predetermined irradiation light. Examples of the combination of LEDs include white light and a light bulb color, or a combination of three primary colors (RGB). In addition, the output of these LEDs can be individually controlled to make the color temperature of the irradiation light variable.

  The substrate 3 is a long plate-like member formed so that a plurality of light sources 2 can be mounted in a row, and as the base material, for example, a general-purpose substrate plate material such as glass epoxy resin is preferably used. Used. On the substrate 3, a terminal portion electrically connected to a wiring pattern (not shown) for supplying power to the LED is formed on the LED mounting surface.

  The cover 4 has a bowl shape in appearance so that the light sources 2 arranged in a row can be collectively covered, and the bowl-shaped concave side surface becomes an incident surface 41 on which light from the light source 2 is incident, The convex side surface becomes the exit surface 42 that emits the light incident on the entrance surface 41. Further, the cover 4 has a protruding portion 42 </ b> A used for attachment to the housing 10 on the incident surface 41 side, and a part of the protruding portion 42 </ b> A is in contact with the mounting surface 12 of the housing 10. The cover 4 is made of translucent polycarbonate or acrylic resin.

  As shown in FIGS. 2A and 2B, the incident surface 41 of the cover 4 has a plurality of prisms 43 that control the light distribution of the light incident on the incident surface 41. The prism 43 is formed so as to collect light in a predetermined direction including the optical axis H direction. Specifically, each prism 43 includes a control surface 44 that refracts light incident from the light source 2 and a non-control surface 45 that is in contact with the control surface 44 and is inclined with respect to the control surface 44. The plurality of prisms 43 are divided into a prism group 43a whose control surface 44 is inclined to the plus side with respect to a direction H ′ parallel to the optical axis H, and a prism group 43b which is inclined to the minus side. The prism group 43a and the prism group 43b are reversed with the desired maximum luminous intensity direction M as a boundary in a cross-sectional view orthogonal to the longitudinal direction of the cover 4.

  In the prism 43 of the present embodiment, the maximum luminous intensity direction M is the direction of the optical axis H, and the prism group 43a inclined to the plus side with respect to the optical axis H and the prism group 43b inclined to the minus side have the optical axis H. Are formed so as to be symmetric. In the vicinity of the optical axis H, the inclination angle θ1 of the control surface 44 with respect to the direction H ′ parallel to the optical axis H is 90 ° or less. Therefore, the prism 43 can collect the light incident on the control surface 44 from the light source 2 in the direction of the optical axis H. On the other hand, since the non-control surface 45 is not formed as such, the light incident on the non-control surface 45 is emitted in directions other than the maximum luminous intensity direction M, which is the optical axis H. Therefore, the cover 4 having such a prism 43 can increase the maximum luminous intensity in the direction of the optical axis H in the light emitted from the emission surface 42 and irradiates a certain amount of light in other directions. be able to.

  Further, the control surface 44 and the non-control surface 45 are smoothly connected by an R-shaped portion (reference numeral R in the drawing: see FIG. 2B). According to this configuration, when a stress is applied to the cover 4 from the outside, the stress is not concentrated in the concave portion (the R-shaped portion) formed by the control surface 44 and the non-control surface 45, and the cover 4 is cracked. Can be suppressed. In addition, since the cover 4 is difficult to break, the thickness d of the cover 4 can be reduced, and the material cost for manufacturing the cover 4 can be reduced.

  The prism 43 has an angle (incident ray angle α: FIG. 2A) formed with the maximum luminous intensity direction M (optical axis H) of light emitted from the emission surface 42 in a cross section orthogonal to the longitudinal direction of the cover 4. In the range of 60 ° or less, the non-control surface 45 is configured to be shorter than the control surface 44. A general LED light distribution used for the light source 2 is a Lambertian light distribution, and the luminous intensity of light emitted from the light source 2 is about ½ in the direction of 60 ° from the optical axis H. Therefore, by increasing the area of the control surface 44 in the angle range where the luminous intensity is high, the light condensing property in the maximum luminous intensity direction M (optical axis H) can be improved.

  Further, the angle θ2 formed by the control surface 44 and the non-control surface 45 is set so as to become wider as the distance from the maximum luminous intensity direction M (optical axis H) of the light emitted from the emission surface 42 increases. If the angle θ2 formed by the control surface 44 and the non-control surface 45 is large, the moldability of this portion is improved and the structure is stable, so that the cover 4 is difficult to break. Note that, in the region of the incident surface 41 where the incident light angle α is larger than 60 °, the light intensity is low as described above, and therefore the light condensing property of the entire cover 4 is reduced even if the light condensing property of this portion is lowered. The decrease in is slight.

  In the vicinity of the maximum luminous intensity direction M of the light emitted from the emission surface 42, the angle θ3 formed by the optical axis H of the light source 2 and the non-control surface 45 is greater than 0 °, and the interval p between the adjacent prisms 43 is It is desirable that the relationship with the height h of the prism 43 satisfies h ≦ p / 2. If the angle θ3 formed by the optical axis H and the non-control surface 45 is smaller than 0 °, the angle of the concave portion (the formation portion of the R-shaped portion) formed by the control surface 44 and the non-control surface 45 becomes a narrow angle. The stress is concentrated on the cover 4 and the cover 4 is easily broken. Therefore, by setting the relationship between the angle θ3 and the interval p and the height h as described above, the control surface 44 and the non-controllable state are secured without securing the inclination angle of the control surface 44 and degrading the light collecting performance. It can suppress that the angle of the recessed part which the surface 45 comprises becomes too narrow.

Furthermore, it is desirable that the relationship between the maximum height h _max of the prism 43 and the minimum thickness d _min of the cover 4 satisfies h _max ≦ d _min . In this way, since a predetermined thickness can be secured in the cover 4, the height of the prism 43 can be suppressed while maintaining the strength of the cover 4, and the necessary amount of translucent material used for manufacturing the cover 4 can be reduced. it can.

  Further, it is desirable that the convex portion 46 formed by the control surface 44 and the non-control surface 45 in the prism 43 is closer to the substrate 3 as the distance from the maximum luminous intensity direction M of the light emitted from the emission surface 42 increases. That is, the cover 4 has a bowl shape that is convex in the light emission direction as a whole, and the prism 43 is formed along the bowl-shaped inner surface (incident surface 41). If it carries out like this, light which can be light-distributed by the prism 43 among the lights radiate | emitted from the light source 2 can be increased, and condensing property can be improved.

  3A shows a light distribution curve when the cover 4 is not used in the lighting device 1, and FIG. 3B shows a light distribution curve when the cover 4 is used. That is, by using the cover 4, the light emitted from the light source 2 can be collected and the luminous intensity in the optical axis H direction (0 °) can be increased.

  In the present embodiment, the cover 4 is configured to have light diffusibility. Specifically, as shown in FIG. 2B, a light-transmitting resin (texture processing or light-scattering agent containing a light scattering agent) is applied to the incident surface 41 or the output surface 42 of the cover 4 (the output surface 42 in the illustrated example). Alternatively, the diffusion treatment layer 47 is formed by applying the sheet.

  As shown in FIG. 4, the cover 4 may be made of a material containing a light diffusing agent 48 such as titanium oxide. The diffusivity of the cover 4 in this configuration varies depending on the thickness of the cover 4, but when the cover 4 has a thickness of 1 mm, the diffusivity is preferably 42% or less.

  According to this configuration, since the emitted light can be dispersed to a certain degree, the occurrence of glare can be reduced. That is, according to the illuminating device 1, the prism 43 formed on the incident surface 41 of the cover 4 can increase the light intensity directly below the illuminating device 1, and the cover 4 has light diffusibility. The glare can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, the description has been made based on the configuration example in which the prism 43 is formed so that the maximum luminous intensity direction M is the optical axis H direction. However, as shown in FIG. 5, the prism 43 may be formed such that the maximum luminous intensity direction M emitted from the emission surface 42 is inclined with respect to the optical axis H. Here, it is desirable that the maximum luminous intensity direction M is inclined with respect to the optical axis H within a range of 10 to 30 °. If it carries out like this, what is called wall washer illumination which irradiates light toward a wall surface by replacing the cover 4 can be performed. In this case, except for the shape of the prism 43, the cover 4 is preferably symmetrical with respect to the optical axis H in a cross section orthogonal to the longitudinal direction of the cover 4. In this way, the maximum luminous intensity direction can be reversed only by reversing and attaching the cover 4 to the housing 10 without changing the attachment direction of the instrument itself. Moreover, although the structure which used LED which is a point light source as the light source 2 was shown, the light source 2 may be a linear light source like a straight tube | pipe type fluorescent lamp, for example, and like organic EL A planar light source may be used.

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Light source 3 Substrate 4 Cover 41 Incident surface 42 Output surface 43 Prism 44 Control surface 45 Non-control surface 46 Convex part which a control surface and a non-control surface comprise 47 Diffusion processing layer 48 Light diffusing agent H Optical axis H of light source 'Direction parallel to the optical axis M Maximum luminous intensity direction R R-shaped portion α Angle formed by the maximum luminous intensity direction of light emitted from the exit surface p Spacing between adjacent prisms h Prism height h _max Maximum prism height d _min Minimum thickness of the cover θ1 Angle of inclination with respect to the optical axis in the direction of maximum light intensity θ2 Angle formed by the control surface and non-control surface θ3 Angle formed by the optical axis of the light source and non-control surface

Claims (9)

A lighting device comprising a light source, a substrate on which the light source is mounted, and a bowl-shaped cover that covers the light source and the substrate,
The light source has an optical axis in a normal direction of the substrate;
The cover has an incident surface on which light from the light source is incident, and an emission surface that emits light incident on the incident surface, and diffuses and emits light from the emission surface.
The incident surface has a plurality of prisms that control light distribution of light incident on the incident surface;
The plurality of prisms are formed so as to collect light in a predetermined direction including the optical axis direction. The prism has a control surface that refracts light incident from the light source, and a non-control surface that contacts the control surface and is inclined with respect to the control surface,
The lighting device according to claim 1, wherein the control surface and the non-control surface are smoothly connected by an R-shaped portion.   The prism is configured such that, in a cross section perpendicular to the longitudinal direction of the cover, the non-control surface is more than the control surface when the angle formed with the maximum luminous intensity direction of light emitted from the output surface is 60 ° or less. The lighting device according to claim 2, wherein the lighting device is short.   4. The lighting device according to claim 2, wherein an angle formed between the control surface and the non-control surface becomes wider as the distance from the maximum luminous intensity direction of light emitted from the emission surface increases. 5.   In the vicinity of the maximum luminous intensity direction of the light emitted from the emission surface, the angle formed by the optical axis of the light source and the non-control surface is larger than 0 °, and the interval p between the adjacent prisms and the height of the prisms. 5. The lighting device according to claim 2, wherein a relationship with h satisfies h ≦ p / 2. 6. The illumination device according to claim 2, wherein a relationship between a maximum height h _{max of the} prism and a minimum thickness d _{min of the} cover satisfies h _max ≦ d _min. .   The convex portion formed by the control surface and the non-control surface of the prism is closer to the substrate as it is away from the maximum luminous intensity direction of light emitted from the emission surface. The lighting device according to claim 6.   The lighting device according to any one of claims 1 to 7, wherein the cover has a texture or a light scattering agent applied to the incident surface or the exit surface.   The lighting device according to any one of claims 1 to 7, wherein the cover is made of a material containing a light diffusing agent.